2 DEPARTMENT OF THE INTERIOR 



2 GEORGE V., A. 1912 



mountain system (from the summit to the Columbia river), and of the Okana- 

 gan and Hozomeen ranges of the Cascade mountain system. Elsewhere, the 

 maps and sections, in their rigid lithography, suggest more certainty as to the 

 run of contacts and as to underground structures than the writer actually feels. 

 As a whole, the results lie half-way between those of a reconnaissance survey 

 arc! those of a detailed survey. 



One of the leading difficulties felt by all workers in this part of the Cordil- 

 lera is the remarkable lack of fossils in the sedimentary rocks. The writer has 

 been able to discover but few fossiliferous horizons additional to the small 

 number already known to Canadian and United States geologists. Many of the 

 correlations offered in the following report are to be regarded as strictly tenta- 

 tive and should not be quoted without reference to the many qualifications noted 

 in the running text. 



Some large proportion of the inaccuracy in maps and sections is due to the 

 fact that for half of the field seasons the writer was provided either with no 

 topographic map or merely with the four-miles-to-one-inch West Kootenay 

 reconnaissance sheet of the Canadian Geological Survey. This sheet is excellent 

 tor its purpose, but was manifestly not intended for the use of the structural 

 geologist, whose topographic-map scale should be at least one mile to one inch 

 in the Selkirk and Columbia mountain systems. First in 1904, the writer was 

 able to use copies of the manuscript Boundary Commission plane-table maps, 

 on the scale of 1 : 63,360. Sheets 1, 2, 3, 4, 5, 12, 13, and 14 were constructed 

 on that basis and are superior in accuracy of geological information to the 

 other sheets. Between the Gulf of Georgia and the western limit of sheet 17 

 the Boundary line crosses a continuous thick deposit of Pleistocene gravels and 

 sands. No other formation is there exposed in the five-mile belt and the broad 

 plain is not represented in the maps. 



Acknowledgments. — The writer was efficiently aided in the physical work of 

 carrying on the survey, during five seasons, by Mr. Fred. Nelmes of Chilliwack, 

 British Columbia. His faithfulness in many a tedious place was' worthy of his 

 sterling work as a mountaineer. During the season of 1903 the writer was 

 similarly assisted in able manner by Mr. A. G. Lang, of Waneta, British Col- 

 umbia. In the field many courtesies and much help were extended by Mr. J. 

 J. McArthur, chief topographer for the Canadian branch of the Boundary 

 Commission; by Mr. E. C. Barnard, chief topographer for the United States 

 branch, and by his colleagues. 



In the office work the writer was aided by many members of the Geological 

 Survey of Canada, and owes much to the personal encouragement of Honour- 

 able Clifford Sifton, Minister of the Interior, during the progress of the survey. 

 In numberless ways the work was forwarded by the able and most generous 

 help of the Canadian Commissioner, Dr. W. F. King, to whom the writer owes 

 the greatest debt of acknowledgment. Professor D. P. Penhallow of McGill 

 University has made thorough study of the collections of fossil plants. The 

 collections of fossil animal remains were, with much generosity, carefully 



